Some devices for removing a sheet from a stack of sheets utilize a partial vacuum created by suction while others utilize a partial vacuum created by a blown air stream. Swiss Pat. No. 435,327; French Pat. No. 2185229 and German Patent Application No. 3220237 are examples of the former, while European Patent Application No. 0032765 is an example of the latter.
The device described in European Patent Application No. 0032765 contains a removal element having several separate recesses, which can be used to feed sheets one by one from a stack to a printing or copying device. A disadvantage of this device is that a relatively large partial vacuum is necessary in the separate recesses to always and reliably separate sheets of different types from the stack. To achieve the relatively large partial vacuum, large quantities of air have to be blown at high speeds through each separate recess. The air pump or compressor necessary for this purpose must have a large capacity and, therefore, will be relatively expensive. Additionally, the air blown at high speeds will cause considerable noise, which can be troublesome and unacceptable in the workplace. It would be desirable, therefore, to design a sheet removal device utilizing a blown air stream such that very reliable operation s achieved with a considerably smaller displacement of air.